package leetcode.problems;

import org.junit.Test;

import java.util.HashSet;

/**
 * Created by gmwang on 2018/7/25
 * 包含重复
 */
public class _0831ContainsDuplicate {
    /**
     *
     * Given an array of integers, find if the array contains any duplicates.
     *
     * Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.
     *
     * Example 1:
     *
     * Input: [1,2,3,1]
     * Output: true
     * Example 2:
     *
     * Input: [1,2,3,4]
     * Output: false
     * Example 3:
     *
     * Input: [1,1,1,3,3,4,3,2,4,2]
     * Output: true
    /**
     *
     * @param nums
     * @return
     */
    public boolean containsDuplicate(int[] nums) {
        HashSet<Object> set = new HashSet<>();
        for (int i = 0; i < nums.length; i++) {
            if(!set.add(nums[i])) return true;
        }
        return false;
    }
    @Test
    public void test() {
        int[] A = {1,2,3,4};
        boolean res = containsDuplicate(A);
        System.out.println(res);
    }

}
